1. Field of the Invention
The present invention relates to a wireless card device, and more particularly to a wireless card device having an antenna device for receiving and transmitting signals of two or more different frequencies.
2. Description of the Prior Art
Various kinds of network systems have become more and more popular nowadays. Heretofore, the computers of the end users are required to be coupled to or communicated with the network systems with or via cable connections. However, the cable connected network systems are inconvenient for both the end users and the network system providers.
Recently, wireless network systems have become more and more popular, and have mostly substituted the cable connected network systems. For entering into or for communicating with the wireless network systems, various kinds of wireless card devices are required to be prepared and coupled to the computers of the end users, and include an antenna device for communicating with the wireless network systems.
However, the typical wireless card devices for the typical wireless network systems normally comprise a single antenna device that may receive and transmit signals of a particular or predetermined frequency only.
However, a number of different frequencies have been provided and used for the typical wireless network systems. For example, at least 802.11a and 802.11b of the institute of electrical and electronic engineers (IEEE), i.e., at least two different frequencies: IEEE 802.11a and IEEE 802.11b have been provided and used for the typical wireless network systems.
For communicating with the wireless network systems of different frequencies, the end users have to purchase and prepare two or more kinds of wireless card devices each of which includes an antenna device that may receive and transmit signals of a particular or predetermined frequency only.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional wireless card devices.